Once Alice has the byte stream she uses it to compute a hash 64487b3448548b7c8a5cfaeb0147bf54. She also creates a full signature using her private key. She then writes this all down in a new TriG document:

Alice then sends the document to Charlie. Charlie is able to take the triples in the graph statement labeled urn:md5:64487b3448548b7c8a5cfaeb0147bf54 produce the same byte stream and verify both the hash and Alice's signature.

Gavin Carothers Opinion

I am unaware of any use case around endorsement or authority that would not require some level of cryptographic signing. Once going down that road it's easy to use the byte stream required by ANY HMAC system to name the set of triples. This sort of use of IRIs containing hashes for identity of arbitrary data is already in wide use today. http://en.wikipedia.org/wiki/Magnet_URI_scheme#URN.2C_containing_hash_.28xt.29